


Wanna See You Work It

by mammothluv



Category: Castle, Grey's Anatomy
Genre: Crossover, Multi, Threesome, Threesome - F/F/M
Language: English
Status: Completed
Published: 2012-02-12
Updated: 2012-02-12
Packaged: 2017-10-31 00:51:12
Rating: Mature
Warnings: No Archive Warnings Apply
Chapters: 1
Words: 2,764
Publisher: archiveofourown.org
Story URL: https://archiveofourown.org/works/338092
Author URL: https://archiveofourown.org/users/mammothluv/pseuds/mammothluv
Summary: <blockquote class="userstuff">
              <p>Two girls and a guy in a bar.</p>
            </blockquote>





	Wanna See You Work It

**Author's Note:**

> Castle and Grey's Anatomy belong to their creators and ABC. I'm not making any profit and no copyright infringement is intended.
> 
> This was written for Porn Battle XIII (Lucky Thirteen) for the prompt Castle/Grey's Anatomy, Kate Beckett/Richard Castle/Meredith Grey, tequila. 
> 
> Many thanks to lone_lilly for the beta work and holding my hand through this threesome.

Kate agrees to drinks in the hotel bar because Castle leans into her when he asks, close enough that she can smell his cologne and feel his breath against her cheek. She’s wound tight after a three hour drive followed by hours of interviews with witnesses that gave them just enough information to keep them chasing the next lead but not enough to send them anywhere worthwhile. And then there’s Castle, Castle who has been staring at her all day in a way that she swears she can almost feel, feather light touches skittering across her skin every time he looks at her.

They need to track down one more witness but all they know is her first name and that she works at a coffee shop that was already closed for the night when they got there. Now they’re at a hotel with adjoining rooms. And, before Castle knocks to ask her to the bar, Kate’s eyes are trained on the door that leads to his room. Because her whole body is tense and her mind can’t stop wandering to all the ways he could help her with that.

The drinks are an excuse, premeditation, the out she knows she’ll need to explain away what’s going to happen tonight. Still, as inevitable as the conclusion to the night may be, something in the sure weight of Castle’s hand on her back as he follows her to the table makes her bristle.

So, moments later, when she sees the blonde sit down at the bar just inches from their table and knock back a shot while eyeing both Kate and Castle with a mild interest which looks like it could spark into something more with the slightest provocation, Kate is introducing herself and Castle before the part of her brain that usually talks her out of rash decisions can kick in.

“Care to join us for a drink, Dr. Grey?” Kate asks, eyes landing on the woman’s name tag.

“Meredith,” the woman says, looking down at the name tag with a frown, then plucking it off before she slides from her bar stool and saunters over to take a seat at their table. “Conference,” she adds, gesturing at the name tag she’s crumpled up and tossed down on the table. “If you ever have the opportunity to attend a cocktail party with 30 surgeons, don't.”

"Boring?" Kate asks.

"Doesn't even begin to describe it."

“You are in luck,” Castle offers, as he motions to the bartender for another round of drinks, “because we just so happen to be very entertaining.”

A half hour and two more rounds later, Kate is scooting her chair closer to Meredith’s, the tips of her fingers brushing against Meredith’s as Kate laughs at her play by play of the dreadful cocktail party she’s just escaped.

It's not until Kate sees the smallest signs of hesitance on Castle’s part that she makes her intentions clear. Someone else might have missed it but she's had over two years to get in tune with the subtleties of his reactions. Even with her eyes on Meredith, Kate catches Castle's brief glance toward the exit, the way his fingers trail nervous patterns in the condensation on his glass.

So, when she leans forward, her fingers wrapping around Meredith’s wrist as her other hand deftly plucks a lime from the bowl in between them, Kate also lets her leg curl around Castle’s ankle. Her heel runs along his pleasantly strong calf muscles.

She risks a glance over at him as she knocks back her shot. He simply raises an eyebrow in her direction and takes a shot of his own.

“We don’t have to do this,” Meredith says.

“What?” Kate asks.

“Pretend to get to know each other anymore. You’re just a couple in a bar and... I’m just a girl in a bar.” There’s a slight bitter edge to the last words but it doesn’t seem directed at them so Kate allows it to pass. They’re not doing the getting to know each other thing, after all.

And it seems they’re not doing subtle either. Fine with her.

“I have a room on up on twelve,” Kate offers.

Meredith shifts slightly, produces a key from the small black purse she’s carrying, says her next words like there’s a competition and she’s won it, “Tenth floor. Mine’s closer.”

Meredith stands and Kate follows suit, watches Castle toss money on the bar, way more than is necessary for the amount of drinks they had. She doesn’t turn to look but feels him follow, a steady presence behind her as always.

In the elevator, Kate pushes Meredith against the wall the minute the doors close, kisses her, lets her tongue run over lips that taste of tequila, salt, and lime. Meredith’s fingers find their way under Kate’s shirt, digging into her lower back and pulling Kate closer. Castle’s pressed firmly against Kate’s back, his hands insinuating themselves between her and Meredith. It’s difficult to tell which of them he’s reaching for and though Kate knows well enough to understand that it’s her, that’s it’s always her, it’s a relief right now the way the lines blur, the way it can almost not matter.

His breath is warm against her ear, his voice deep, practically a rumble when he whispers, “So many layers to the Beckett onion.” And then his lips move to her neck, traveling light, sloppy trails against her skin.

Somehow they manage to untangle just as the elevator doors open.

Once they’re in Meredith’s room, it’s Meredith who has Kate against the wall. Then it’s a blur of lips and tongues and teeth and Kate isn’t sure if it’s the tequila or the situation that’s making her feel this dizzy kind of rush that’s spreading through her entire body.

Castle is leaning against the wall opposite them. He’s still but his there’s no doubt his attention is focused on them, like he’s not quite sure he wants to interrupt. Even if the intensity of his gaze hadn’t given him away, the obvious bulge in his pants tells Kate he’s just as in this as she is.

“Don’t be shy, Castle,” she drawls, untangles herself from Meredith and takes a few steps to close the distance between herself and her partner. Kate hooks two fingers into the waistband of his pants, pulls him close enough that his chest presses her own, feels the hitch of his breath in response. She pops a button, tugs at his zipper, hooks fingers into his waistband again, this time pulling down, determined to shed the layers between them.

If he was hesitating before, he’s caught up with her now. He responds in kind, fingers working the buttons of her shirt, pausing in between to trail newly revealed skin, his movements strong and sure. Kate shudders. Her hands have stilled at his waist but now she reaches down, cups him through his boxers, his hips jerk toward her in response.

Tomorrow when she’s sober she’ll push the thought aside, as she always does, but for a second she allows herself to wonder what it means that it’s so much easier to let him close with the security of someone in between.

“Everyone...” Meredith’s voice pulls Kate from her thoughts. Castle’s eyes are dark now, a predatory edge to the way they narrow as he regards her. Kate turns her head to see the other woman swaying toward them, bottle of tequila in hand. They didn’t bring it from the bar. She must have had it in the room already. “...is still wearing far too many clothes.”

Meredith takes a swig of tequila from the bottle and then hands it to Kate who does the same as she watches Meredith reach for Castle’s shirt, sees him raise his arms to help her lift it off him.

And it shouldn’t be as hot as it is when she watches Meredith stand on her tiptoes and pull Castle into a long kiss, one of Meredith’s legs wrapping around Castle to pull him closer. But Kate feels her stomach tighten, her blood rush in response. Her hand moves to the apex of her own thighs of its own accord. And, Meredith is right, the clothes are a problem. Kate unbuttons her pants and kicks them off along with her shoes.

Castle is unzipping Meredith’s dress and then Kate watches it slide down, the slow reveal of skin and curves. Heat rushes through her body in response, desire coiling inside her.  
When they’re all completely undressed, Meredith grabs both their hands and pulls them toward the bed. She allows herself to fall backwards when the backs of her legs collide with the mattress, inches back until she’s in the center of the bed, eyes on Kate and Castle the entire time.

Kate follows, positioning herself on her knees directly in front of Meredith. She turns her attention to Castle then. He’s still standing at the edge of the bed and she takes allows her gaze to travel his chest, his strong arms, his obvious arousal. Her fingers twitch to touch him, knowing tonight will be the only opportunity she allows herself. She’s mapping out the paths she wants to travel with hands, and tongue, teeth.

“You coming or what, Castle?” she asks, tilting her head slightly to indicate the direction in which she thinks he ought to be moving.

He simply shakes his head, his lips quirking slightly upward as he says, "I want to watch you."

Of course. He’s not hesitating at all. She should have known better. It's his writer’s eye, his need to catalog every detail of her. And maybe she should object, maybe it should all feel a little too much like bad porn. But he’s looking at her with that same eager interest he does when she’s interrogating a suspect, like he just wants the opportunity to see her in action, like this might be the thing that will give him some valuable insight into her that he's somehow missed before despite exacting study.

She wonders which parts of this will make it into the next Nikki Heat. Will Rook part Nikki’s thighs the way she’s parting Meredith’s now, hands slowing, teasing soft skin along the way? Will Rook’s tongue tease Nikki’s folds the way she’s doing now, making Meredith shudder underneath her?

(It’s not all about Nikki anymore. She knows. But her life feels easier when she allows herself to ignore that fact.)

There are some things he can't observe and suddenly, she'll blame it on the tequila or maybe the way Meredith's legs slide up, ankles wrapping around to brush against Kate's legs, Kate will blame it on a lot of things but the point is suddenly she's feeling generous. So, after her tongue finds Meredith’s clit, trails circles around it, Kate smiles against the warm skin of Meredith's thigh. "She tastes like tequila,” she says.

Above her, Meredith laughs. Kate feels the vibration. “I think the tequila is you,” Meredith offers, voice low and rough.

“Warm,” Kate continues. Castle’s eyes are half-closed but they’re definitely focused on her, waiting on her next words, hand wrapped around his hard cock, stroking slowly.

“Wet,” she says as she enters Meredith with her tongue then trails upward, spreading Meredith’s arousal as she goes, tongue flicking against Meredith’s clit. Meredith rolls her hips underneath Kate in response, reaches down to tangle her fingers in Kate’s hair.

Meredith lets out a long, guttural moan. She’s vocal, extremely vocal. And Kate feels her own arousal building with every word, every incoherent sound, every shudder of Meredith’s body underneath Kate’s tongue.

Her hands have slid around to cup Meredith’s ass and she grips harder now, fingernails digging into sensitive skin as Kate’s tongue continues to work. Meredith whimpers in response, then bucks as she comes with an exclamation of, “Fuck, yes.”

Kate sits up then, attention turning to Castle who looks as dazed and breathless as she feels.

"Castle, surely you've learned in your time with me that observation alone won't get you where you need to go."

"True, Detective Beckett." Meredith raises an eyebrow at Castle's use of Kate's title but doesn't comment. "You've always done an excellent job demonstrating the merits of hands on police work."

Kate leans up, reaches toward him, fingers closing around his wrist and pulling him toward her. She allows herself to collapse back, prone on the bed and he follows, his hands falling on either side of her so he’s hovering just inches above. Next to them, Meredith props herself up on one elbow, reaches out to trail one hand over Castle’s bicep and up to his back. Kate can feel the heat of him, hear every one of his steady shallow breaths.

“Well,” Kate says, hips arching upward and legs parting in invitation, “get to work then.”  
He does not need further encouragement, he leans down for a kiss as he enters her, his lips on hers are gentle in a way that’s almost incongruous with their current situation.

Kate’s mouth opens, lips, breath, and tongue forming around the familiar edges of his name as he moves inside her. She could suffocate under the weight of it, the meaning inherent in the way the spaces between them so easily dissolve, if not for the gentle distraction of Meredith’s tongue trailing her collar bone.

Meredith’s arm snakes in between them, her fingers finding Kate’s clit and stroking just as Castle speeds up his rhythm. Kate lifts her hips, rising to meet Meredith’s touch and the change is just enough that Castle hits exactly the right spot.

Again.

Again.

Kate holds a breath, releases as her whole body shudders with an orgasm that leaves her wondering why she doesn’t do this threesome thing more often because two people working to make her come at once, well, it’s really kind of amazing.

Castle follows her then, moans as he comes inside her. And Kate doesn’t resist the urge to reach out and pull his face toward her own. She kisses him then, all tongue and teeth and things she won’t say in the sober light of day.

 

Kate wakes the next morning alone, back in her own room, her mouth still tasting of both of them. Can’t quite bring herself to regret last night as she uncurls, stretching pleasantly aching muscles.

She showers and dresses then makes her way to Castle’s door. They still have a job to do after all, despite the pounding in her head.

She braces herself for awkward as she knocks, wonders how and if they manage to find their balance again after last night. But he has the small coffee maker the hotel has provided on, hands her a cup before she's even through his entryway. Kate feels her equilibrium return, the ground steadies under her feet as the first sip warms her throat.

“Last night,” she starts.

“Awesome,” he supplies, emphasis on the first syllable of the word and wink to punctuate.

“Is never going to happen again,” she corrects, her voice firm and commanding.

“Sadly, I agree,” he says. “Once in a lifetime occurrence. Best threesome ever.” His hand sweeps in front of him as if he’s imagining the last three words on a marquee, and her lips curl upward despite her efforts to keep her expression neutral.

“No, Castle. What I mean is...” she stumbles over the words, the fog in her brain not yet cleared by the coffee she’s sipping. “I don’t want you to think that you and I...” She doesn’t say Josh’s name, can barely bring herself to think it after last night but he’s there in between then nonetheless, heavy as always in a space she won’t let Castle cross.

“Oh please, Beckett. Everyone knows out of town threesomes don’t count.”

He’s telling her he knows where her head is, letting her off the hook. It doesn’t make her feel any less guilty but, still, better somehow. It’s part of their dance and she falls into step easily. Even though what he’s just said is the Castle version of the argument she was about to make, Kate sighs and rolls her eyes in response. Moves from her position against his wall and opens the door.

When they settle into the elevator, Castle pushes the button for the ground floor as he says, “Still, awesome.”

“Amazing,” she agrees, her lips inches from his ear as she whispers. And then the elevator doors open and she strolls out at full speed. “Come on, Castle. We’ve got a witness to interview.”


End file.
